Sorter



June 7, 1949. c. F'. MULLEN 2,472,718

I son'rsn Filed Aug; 25, 1944 5 Sheets-Sheet 1 I N V EN TOR.

Cbar/es F MEI/ en A TTORNE Y.

June 7, 1949. c. F. MULLEN 2,472,718

7 son'mn- Filed Aug. 25, .1944 5 Sheets-Sheet 2 INVENTOR.

BY C/mr/ea E Miler) AT TORNEK June 7, 1949. c. F. MULLEN 7 ,7 8

SORTER Filed Aug. 25, '1944 I 5 Sheets-Sheet 3 INVENTOR.

By Charles F1170??? ATTORNEK mam June 7, 1949.

G. F- MUL N ORTE Filed 1944 I N V EN TOR. Char/es E Mullen BY met/M,

A TURN Patented June 7, 1949 UNITED STATES PATENT OFFICE SORTER Charles F. Mullen, Long Branch, N. J., assignor to Republic Aviation Corporation, Farmingdale, N. Y., a corporation of Delaware Application August 25, 1944, Serial No. 551,134

11 Claims.- 1

This invention relates to rivet sorters and contemplates a machine which will rapidly separate rivets according to their shank lengths, so that masses of rivets having shanks of assorted and varying lengths may, in passing through the sorter, be separated and rivets having shanks of the same length segregated into isolated groups.

The instant invention has in view the continuous, positive, measurement of the shanks of the rivets bein sorted whereby rivets having shanks of the same length are selected and grouped automatically.

To that end, it is proposed to feed the rivets to be sorted to and along a path having stations at intervals, each station being alloted to a predetermined length of rivet shank. The rivets are positively held and retained in their relative positions, until the arrival of each rivet at the station alloted to the length of its shank, whereupon it is individually released and ejected from the path to join a group of rivets having substantially the same length.

With the above and other objects in view, as will be apparent, this invention consists in the construction, combination and arrangement of parts all as hereinafter more fully described, claimed and illustrated in the accompanying drawings, wherein:

Fig. 1 is a plan view of the rivet sorter forming the subject matter of the present invention with the hopper coacting therewith removed:

Fig. 2 is a side elevation thereof:

Fig. 3 is an enlarged transverse section along line 3.3 of Fig. 1 to illustrate the cooperation between the rotary rivet carrier and the mechanismfor measuring and ejecting rivets from the carrier according to the shank length thereof, to-

gether with the source of power for such ejection:

Fig. 4 is a vertical section enlarged for clarity taken along line 4-4 of Fig. 1 through the hopper and the feeding mechanism by which rivets to be sorted are conveyed from the hopper and delivered to the carrier:

Fig. 5 is a transverse section taken along the.

line 5-5 of Fig. 4 to illustrate the feeding mechanism and the means for removing improperly placed rivets from the feed:

Fig. 6 is a development of the measuring rail to graphically show the comparative panel lengths by which the sorting measurement of the rivet shanks is accomplished:

Fig. '7 is an enlarged schematic sectional View through the rivet carrier and measuring rail to illustrate the coaction between the rivet carrier, rivet shank and the measuring rail: and

Fig. 8 is a plan view enlarged for clarity of a fragment of the periphery of the rivet carrier showing the cooperative positions of the measuring rail, the carrier and a rivet supported thereby, as well as the formation of the individual rivet mass of rivets are, successively and individually fed to a continuously rotating carrier to be so received and seated in pockets or recesses in the periphery thereof that their shanks project be-.

low the plane of the carrier. A stationary retaining and measuring rail surrounds the carrier and comprises a seriesof panels of graduated heights whereby the upper edge of the rail as a unit is stepped or incremented, each step or increment corresponding to a given length of rivet shank. The position and construction of this railv is such that it overlaps the shanks of the rivets seated in the pockets or recesses of the carrier, the rivet shanks thus coacting successively with the several panels of the rails until each arrives at a panel not high enough to overlap its shank. At

this point the rail ceases to retain the rivet on the carrier and it is free to pass over the upper edge or end of that particular panel ofthe rail. An ejection force is successivelyapplied in alignment With each panel to the shanks of the rivets seated on the carrier whereby each rivet will be ejected at each panel unless this ejecting force is counter acted by the panel in overlapping the rivet shank. Hence, each rivet on arrival at the first panel of the rail which fails to overlap its shank is ejected from the carrier over the upper end or edge of said paneland is ultimately deposited in a receptacle allocated to that panel and in which is received all rivets similarly ejected from the carrier at that point.

In the drawings, I0 designates a frame of any suitable construction on and in which is mounted a vertical shaft l I rotated by a belt or other drive I 2 from the motor [3 by and through any adaptable speed reduction mechanism I2. The motorl3 is mounted for bodily movement upon a threaded shaft is which may be rotated or controlled by a crank 15. This is an example of a mechanism for driving the shaft II which incorporates means to adjust the tension on the belt l2, it

being obvious however that any other type and construction of drive may be employed for rotating the shaft I I at any desired speed.

A sleeve I6 surrounds and is fixed to the upper end portion of the shaft I I for rotation in unison therewith. This sleeve I6 supports a series of radiating vanes I! and a horizontal carrier I8, positioned below and attached to the vanes I? in any suitable manner forrotationwin. a horizontal plane with the shaft II and sleeve EIB. At itsperiphery the carrier I8 is provided with an extension or plate I 9 of less thickness than said carrier:

and projecting beyond the limits of the latter.

This extension I9 is fixed to the carrier I8 and is a flush with and forms a continuation of its undersurface.

The edge of this extension I9 is provided with:

a series of recesses or pockets 2!), each for the reception of a single rivet (Figs. 1, '7 and 8). One wall 2| of each recess 20 is substantially straight and at the time of the reception or the discharge of a rivet lies substantially. parallel to the path ofmovement of the rivet in entering or leaving the recess 20. The opposite side wall 22 of each pocket or recess 20 is curved away from'the opposite wall-2I and, as will be hereinafter evident,

the walls coact to assist in'the removal of a rivet from the feed and in theseating of it in the rece'ss-Zll. The wall 22 is so formed that no rivet removed from the feed jams or becomes engaged between the carrier I8or its extension plate I9 and the measuring and retaining rail during the.

rotation of the carrier.

Suitable roller bearings 23 may be provided and are positioned'between the sleeve I6 and a fixed member 24' of the frame structure I0, whereby the" former together with the carrier I8 may freely rotate relative to the frame. The radial vanes" I1; fixed to the sleeve I6, brace the carrier I8" to overcome any distortion thereof or any tendency it may have to vibrate or rotate out of aplanetransverse to the longitudinal'axis of the shaft II. Manifestly the sleeve- I6, carrier I8; vanes I1, and extension plate I9 constitute a unitary structure driven from and rotating in unison with the shaft II.

Below the rotary carrier or table I8 is thestatlonary or fixed frame member 24 braced'by outstanding or radial webs 25 and surrounding and housing the shaft II- and the lower'operative end ofthe sleeve I 6. The shaft II and all parts fixed toit as abovenoted rotate within this stationary or fixed member 24. An outstanding flange 25' is attached to the stationary'member. 24 and;

supports a stationary table 21 at its. periphery, saidtable being also supported, adjacent its outer edge by elements of the frame I0. This stationary table 21, onits' upper surfaceand in approximate alignment with the outer periphery of the extension plate I9 of the rotary carrier I8, isprovided with a concentric upstanding mounting block 28. To the outer surface of this mounting block is secured the measuring rail 29'by means:

of the bolts 30 passing through thelower portion.

The rotation of the carrier I8 and its extension plate I9 moves the rivets seated thereon in spaced relation, with their shanks projecting below the plane of the carrier and plate, just to the rear of he upper edge of the rail 29, so that the rail overlaps the shanks of the rivets during at least part of a single rotation of the carrier. So long as the rail overlaps .the shank of a rivet that rivet remains. seated'on: and properly positioned in the pocket or recess of the carrier and to that extent the; rail 29 retains the rivets in place on the carrier against any and all forces tending to dislodge or eject them.

In order to positively measure the shank of each'rivet and to release all rivets having shanks of..thecsame length for ejection from the carrier I8 at the same point in the path of rotation of the carrier. the rail comprises a series of panels 29each, as above noted, corresponding to a single length of rivet shank. These panels 29' are of graduated heights, the lowest or shortest being at oneend of the rail 29 and byprogressive increments to the heights of the panels the highest .or tallest at the opposite end of the rail. Thus the upper edgeof the rail 29, which is the edge which overlaps the rivet shanks and retains the rivets. properly positioned on the. carrier I8, is stepped each step being in an. individual horizontal plane different from the horizontal planes of the other steps and each step representing and determining a single rivet length. During the movement of the rivets with the carrier I8 the shank of each rivet being sorted successively passes each panel 29 until. it arrives at a. panel that does not overlap its shank. whereupon it is free to. be ejected from its recess or pocket 20.

over the upper edgecf said panel. In this manner the length of. the shank of each rivet is measured andreleased for ejection to join an isolated. group of rivets having shanks of the same length. Manifestly the rail 29 may consist of a combination of assembled abutting independent panels 29 or may comprise a single. unitary strip of material having its upper edge stepped to create the operative upper ends of the panels 29.

In Fig. 6 the measuring rail 29 is developed to illustrate the panels 29' and their respective heights in a single plane, it will be observed; while in Fig. 3 it is shown in its operative position with extremities abutting and forming a continuous wall adjacent the edge of. the plate I9 and concentric to the carrier I 8, and plate I9. It is manifest that more than one retaining and measuring rail 29 may be provided for each carrier I8, in which event the several rails 29 would combine to form a single concentric Wall adjacent the edge of the extension plate I9 and a feed should be provided for each such section of the rail. Of course it is to be understood that the variation or graduation of the height of the several panels 29 is shown as being relatively small and that is because the variation in length of rivet shanks is not very great but it is especially manifest that this sorter is not limited in its applications and use solely to rivets and that it may readilybe applied to the sorting of any headed article in which event the variations in the respective heights of the panels 29' may be far greater. the panels 29 are dictated and determined entirely by the character, size and nature of the articles to be sorted.

To the rear of the measuring rail 29 and upon the upper'surface of the mounting block 28 below In short the respective heights of the outer edge of the rotary carrier or table I8 is mounted a continuous concentric manifold 32 to which air under pressure is supplied from any suitable source (Fig. 3). For example a main pply pipe 33 for air under pressure may lead to a distributor 34 from which a pipe 35 leads to the manifold 32 whereby a relatively high internal pressure may be established in the manifold. The manifold 32 is stationary, continuous and concentric to the stationary table 21. The rotary table or carrier I8 and its extension plate l9 rotate over and above the manifold 32. A nozzle or jet 36 is fixed to the outer wall of the manifold 32 for and in alignment with each panel 29' of the measuring and retaining rail 29 to terminate adjacent or adjoining the outer surface of the extension plate is immediately to the rear of the path of movement of the rivets carried thereby. Air under pressure from the manifold 32 constantly passes from these nozzles or jets 36 to successively impinge against the shanks of the rivets carried in front of the jets by the extension plate it. So long as the shanks of the rivets supported by the plate It are overlapped by the panels 29' of the measuring and retaining plate 29, the rail 29 prevents dislodgment or ejection of the rivets from the recesses or pockets 2!! by the air from the jets or nozzles 36 but when a rivet, aligns a panel 29' of the carrier plate 29 which does not overlap its shank in any degree, the air from the corresponding nozzle or jet 36 expels or ejects the rivet from its recess or pocket 28 and causes it to pass over the upper edge of that panel 29 as shown in Figs. 3 and '7. If found advantageous several jets 36 may be provided for each panel 29' or for selected panels in which event they are aligned vertically to act simultaneously on the shank of the rivet.

Thus the rivets are sorted to length not by the position of the air jet or jets but by a positive element, towit, the measuring rail 29, the increments of the panels 29 of which determine the individual lengths of the several rivets sorted.

Afiixed to the stationary table 2'! adjacent to its periphery are a series of chutes 31, one chute being provided for each panel 29 of the measuring rail 29. The outer extremities of these chutes are covered by the plate 38 which prevents the rivets discharged from the extension plate is to a chute 31 from leaving the chute. Rivets which are discharged over any particular panel 29' of the measuring rail 29 immediately pass into the'chute 31 coacting with that panel under the impetus imparted to the rivet by the air from the corresponding nozzle or jet 36.

Below the stationary table 2'1 which carries the chutes 3? is a secondary table 39 fixed to the frame I0 and resting parallel to the table 21. This secondary table 35 is provided with a series of removable receptacles 40, one receptacle being aligned with each chute 31 and consequently with each panel 29' of the measuring rail 29. The rivets ejected from the several recesses or pockets 2!] of the carrier plate is by air from the nozzles or jets 36 pass through the appropriate chutes 31 and drop into the corresponding receptacles 4E. Handles 4! are provided on the receptacles for the ready 'manipulation and removal thereof.

For the feeding of the unsorted rivets to the constantly rotating carrier l8 and extension plate M, a hopper 42 is positioned at a convenient point adjacent the periphery of the carrier or rotary table I8--l9 and is sufiiciently above the plane of rotation thereof to insure feeding of the rivets to the table principally by gravity. This hopper 42 is mounted for rotation upon a suitable supporting structure 43 and is rotated by any type of drive such as a pulley 44 and a drive belt 45, the latter being driven by and from any suitable means. Within the hopper 42 is a series of baffles or buckets 4t fixed to the hopper and positioned to drop the rivets against and upon the reception end of a feed during the rotation of the hopper. A chute or fixed baffie 4'! is provided adjacent to the open end of the hopper to prevent any escape or discharge of rivets from the hopper except through the feed.

The feed which conducts the rivets from the hopper 42 to the periphery of the extension plate IQ of the carrier consists of a pair of spaced tracks 48 sloping downwardly from a Point within the hopper to a point adjoining the extension plate, the shank 49 of each rivet being received between these tracks while the head 50 rides on the upper surfaces or edges thereof. These tracks 48 extend into the hopper 42 to a point adjacent or near the rear wall 5| thereof, Where they terminate above the axis of the hopper. At this end a pair of divergent plates 52 are secured to the feed, one upon each of said tracks 43 forming the feed, so that as the hopper rotates the buckets or bafiles 46 will carry the rivets within the hopper upwardly to a point above the plates 52 to drop by gravity upon the plates 52. As soon as the rivets contact the sloping plates 52 they gravitate towards the tracks 48 whereupon most of them become properly seated with their shanks 49 between the tracks and their heads 50 resting upon the upper edges ofthe tracks.

Any rivet which does not become so seated either drops oil the tracks after leaving the plates 52, or, in the event some rivets remain on the tracks and out of proper position, they may be removed from the tracks 46 and returned to the hopper 42 by the air jets 53 positioned to one side of the tracks 48.

This air jet 53 is positioned Within the hopper and air is conducted to it by the pipe 54 extending from the distributor 34 around the open edge of the hopper to a position within the hopper. Fig. 4 discloses that the jet 53 is between the open end of the hopper and the sloping plates 52, so that all misplaced rivets are dislodged by the air jet and will drop into the hopper and are prevented from leaving it by the fixed balile 4'1. This baffle 47 also acts as a chute for the placing of unsorted rivets within the confines of the hopper.

Thus all rivets properly positioned in cooperation with the tracks 48 gravitate successively along the tracks 48 to a point adjoining the periphery of the extension plate I 9 as illustrated in Fig. 1. Since the extension plate It rotates transversely of the feed, the rivet being delivered by the feed first contacts the curved wall 22 of a pocket or recess 20 and upon the further rotation of the plate 19 the rivet moves inwardly upon the curved wall 22 and is completely removed from the feed by the straight wall 2!. Thereupon the rivet is seated in a pocket or recess 29 where it is held from displacement by the measuring and retaining wall 29 until it reaches a panel 29 having a height that is insufficient to overlap the rivet shank so that the rivet may pass over the edge of the rail into the appropriate chute 31, all as aforesaid. v

The lower ends of the tracks 48 are cut away,

as at55, to produce the relatively narrow necks 56jadjoining the discharge ends thereof and also the mounting or anchoring lips 51. A support sails secured to the fixedtable 21 below the discharge extremities of 'the tracks 48 and the lips l of the tracks 48 are fixed to the upper surface thereof by any suitable means, such as the bolts 59". To secure minor adjustments of the angle of the tracks 48, an arm 6i) ispivoted to the support 58 and at its outer extremity 6| bears against the ends of th tracks 48. Between the support 58 and the extremity 61 of the arm 60 is an adjiistrnent 62 comprising a turnbuckle or equivalent device, the adjustment of which swings the arm 50 and its extremity 61 about the pivot 63. Iffthe turnbuckle 62 is adjusted to swing the extremity SI of the arm 69in an upward direction (Fig, 4) the relatively 'narrow necks 56 of the tracks are flexedlunder the pressure of this adjustment to regulatein a small degree the angular disposition of the edges of the tracks 48 of the feed. Reversely if the adjustment 83 is operated in the reverse direction the tracks 48 will move downwardly under the resilience of the flexed neck 56. This adjustmentdoes not have to be of very large scope'or range so that the necks 56 of the tracks are at no time very extensively flexed.

'To'hold and retain the rivets on and between the tracks 48, at or near the point of successive delivery to the recesses or pockets of the plate I 9, a cover64 is positionedabove the upper edges of the tracks' 48 adjacent the discharge end of the feedand is spaced therefrom a distance equal to the thickness of the heads 50 of the rivets. This cover comprises a strip of metal removably pivoted at 65 to the tracks, the pivot 65 being so situated that the inner terminal of the cover is properly spaced from the edges of the tracks. Adjoining the outer ends of the tracksa spring snap 66 is secured to the tracks between which the cover (it is releasably engaged, thus determining the distance between the tracks and the cover at the discharge end of the feed. The outer extremity of the cover extends over the plate l9 (Fig. 4) so that the rivets upon leaving the tracks and becoming engaged by the plate, are held by the extension 6'! of the cover and prevented by itfrom moving upwardly or turning out of the plane for proper seating in the pockets 20. This extending end 6! of the cover is provided with a handle 68 for the manipulation of the cover. Manifestly if the rivets are properly positioned on and between the tracks 48 and gravitate downwardly toward the rotary carrier l 8-49 the heads in passin nder the cover are held in proper position in contact with the tracks 48 and the extension 61 prevents rotation or displacement of the rivets until they successively seat in the rece'sses or pockets 20.

It will be observed that the tracks 48 at their discharge ends become substantially horizontal, so that immediately preceding their release from the tracks the rivets are not in fact fed by gravity. To assist the feeding of the rivets along that part of the feed immediately preceding the point of discharge a pipe ll! leads from the distributor 34 to a point at about the beginning of the horizontal portions of the tracks 43 where it directs an impelling stream of compressed air on the shanks of the rivets which successively forces them toward the carrier i8 l9.

If it is desired to have access to the feed, the cover 64 may be lifted by th handle 68 thereby becoming disengaged from the snaps or fasteners 86 whereupon it may be swung upwardly about the hinge 65. On the opposite side of the hinge 65 of the cover '64 is'a guiding lip'or flange 69' which directs the'heads of'the rivets upon the" tracks to a'point where they are engaged between the upper edges of'the tracksand'the cover 64.

While the present invention has been shown and described in the sorting of rivets it manifestly has equal utility in the sorting of headed articles of any kind such as nails, bolts, etc.

What is claimed 'isi' 1. The combination with a movable carrier having means for the'reception and support of rivets and fixed means at each step in the railedge to successively act upon the shanks of rivetssup-' ported by the carrie'r'to eject them from the carstationary retaining rail coacting'with said car-'' rier to overlap the shanks of the rivets therein, the edge of said rail being'provided with graduated steps to permitthe individual release of the rivets supported bythe carrierfrom theretaining action of the rail, fixed ejecting'means at each step to successively and independently act upon the rivet shanks supported by the carrier to eject them upon alignment witha' step of the rail not overlapping the shank, and means individual to each step for receiving the'rivets ejected.

3. In a rivet sorter the combination with a. rotary carrier; of means for feeding rivets in'dividually to the carrier, means-for individually supporting each rivet'on the carrier with its' shank extending beyond the 'plane of the carrier, a stationary measuring and retaining rail "concentric to said carrier, a series of steps of varying heights in the upper edge of said rail, each successively overlying the shanks of the rivets supported by the carrier to retain said rivets on the carrier, and ejecting means positioned for cooperation with each' step effective to discharge any rivet freed of the retaining action of said rail.

4. In a rivet sorter the combination with'a rotary carrier, of means for seating rivets indi-- vidually at the periphery of said rotary carrier with their shanks projecting below the plane of the carrier, a stationary retaining and measuring rail concentric to said" carrier including a. series of panels each of a different height terminating at points below the plane of the carrier to sue cessively overlap the shanks of'the rivets seated on the carrier, and a stationary ejecting means coacting with each panel tending to eject each rivet over the upper edge of said panel and effec tive to so eject any rivet having its shank freed of said panel. e

5. In a rivet sorter the combination with a rotary carrier, of means for seating rivets individually at the periphery of said rotary carrier with their shanks projecting below the surface of the carrier, a stationary retaining andmeasuring rail concentric to said carrier including a series of panels each of a different height-and terminating at a point below the plane of the carrier to overlap the shanks or the rivets seated 9 on the carrier, and an air jet positioned under the carrier at each panel to successively direct an air stream against the rivet shanks to eject all rivets freed from the retaining action of the rail from the carrier and discharge them over the upper dge of the corresponding panel.

6. In a device for sorting headed articles according to the length of their bodies, the combination with a constantly moving carrier having recesses for the reception of articles to be sorted with their heads resting on one face of the carrier and their bodies projecting beyond the opposite face thereof, of a stationary retaining rail coacting with said carrier having a series of increments of graduated heights on its upper edge to overlap the projecting bodies of the articles to retain them on the carrier until the length of the body and the height of the increment are such that the former is freed of the latter, and a constantly functioning ejecting means coordinated with each increment effective when a projecting body is freed of the retaining action of the rail.

7. The combination with a rotating carrier having series of spaced, open pockets in its periphery each for the reception of the shank of a rivet, of a stationary rail concentric to said carrier, a series of graduated increment-s on the upper edge of said rail to successively overlap and ultimately release the shanks of the rivets in said pockets, a compressed air manifold disposed below said carrier, and a jet on said manifold individual to each increment to constantly direct an air stream from the manifold toward the corresponding increment.

8. The combination with a rotary carrier having series of spaced open pockets in its periphery each for the reception of the shank of a rivet with the major portion thereof projecting below the bottom face of the carrier, of a stationary rail concentric to said carrier and situated below the plane of the latter, a series of graduated increments on the upper edge of said rail to overlap and successively release the shanks of the rivets in said pockets, a compressed air manifold disposed below said carrier, a series of air jets carried by and communicating with said manifold, at least one jet being aligned with each increment to direct a constant stream of air across the periphery of the carrier toward the increment, and means for feeding rivets to be sorted successively to th pockets of the carrier,

9. The combination with a rotary carrier having series of spaced, open pockets in its periphery each for the reception of an article with a portion thereof projecting from one face of the carrier, of a stationary rail concentric tosaid carrier, a series of graduated increments on one edge of said rail to successively overlap and release the projecting portions of said articles, a compressed air manifold disposed below said carrier, a series of air jets carried by and communicating with said manifold, at least one jet being aligned with each increment to direct a constant stream of air across the periphery of the carrier toward th increment, a receptacle individual to each increment positioned on the opposite side of the rail to the compressed air manifold, and a feed successively to deliver articles to be sorted to the pockets of the carrier.

10. The combination with a rotary carrier having spaced, open pockets in the peripheral edge thereof, of a feed for delivering rivets individually and successively to these pockets and seating them therein with their head-s resting flush against the top surface of the carrier and their shanks projecting beyond the bottom surface thereof, a stationary measuring and retaining rail concentric to said carrier and having progressively graduated increments on its upper edge to coact with the shanks of the rivets on the carrier to retain them in the pocket-s of the carrier and to release all rivets having shanks of the same length at the same point in the rotation of the carrier, a stationary compressed air manifold concentric to and under the outer edge portion of said carrier, at least one air jet carried by and communicating with said manifold for each increment of the rail to direct a stream of air under pressure across the vertical plane of the periphery of the carrier toward the corresponding increment through which the shanks of rivets on the carrier must successively pass, and a chute coordinated with each increment to receive rivets projected over the increment by the air jet aforesaid.

11. The combination with a rotary carrier hav ing spaced, substantially semicircula'r open pockets in the peripheral edge thereof, of a gravity feed to successively deliver rivets to said pockets whereby the head of each rivet rests on one face of the carrier and its shank passes through the pocket to project beyond the opposite face thereof, a stationary compressed air manifold disposed adjacent said carrier, a series of spaced air jets projecting outwardly from said manifold to terminate adjoining that face of the carrier beyond which the rivet shanks project, a stationary concentric rail cooperating with said carrier, having its height gradually reduced by a series of steps each step representing the length of a rivet shank and designed to overlap all shanks having a greater length, and a chute coacting with each step to receive all rivets projectecl over that step by the corresponding air jet.

CHARLES F. MULLEN.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Publication in American Machinist, 8, 1943, pages 107, 108.

July 

